Metal Sales Magna-Loc 180 - Manual (Page 14)

PML-14
MAGNA-LOC
© Metal Sales Manufacturing Corporation/ Subject to change without notice/ Effective Date 9/11
800.406.7387 (Corporate Office) • www.metalsales.us.com
Proper design and installation of vapor barriers and ventilation systems are important to prevent condensation and the resulting
problems of moisture damage and loss of insulation efficiency.
Condensation occurs when moisture laden air comes in contact with a surface temperature equal to or below the dew point of
the air. This phenomenon creates problems that are not unique with metal buildings; these problems are common to all types of
construction.
The underside of the metal roof on a typical metal building (no attic) should be protected from condensation by insulating with a
faced insulation. This should reduce the potential of condensation forming on the underside of the panels.
On buildings that have an attic space or are being retrofitted with a metal roofing system, vents should be placed at both the eave
and peak of the roof in order to prevent a buildup of moisture (humidity) in the attic space.
VENTILATION
Typical Metal Building (No Attic)
Vent
Vent at wall Vent at eave
Building with Attic or Retrofitted
Vent
Insulation
In most cases insulation is installed directly under roof panels. Insulation is recommended on all applications to act as a sound
barrier, prevent condensation, and increase insulating value of a roof system. If insulation is not used some mans of damping the
sound should be used
Many different types of insulation can be used with the metal roof panels. Blanket, batt, rigid, and reflective insulation are just to
name a few. Please contact your insulation supplier for specific recommendations on installation of insulation and vapor barriers.
When applying a compressible type of insulation over open framing members. Rigid thermal blocks can be used to help eliminate
heat lost at purlin locations.
INSULATION
Compressible Insulation
Area of least resistance to heat loss
Purlin
Thermal block
Magna-Loc Panel
Resistance to heat loss is increased
CAUTION
Use extreme care when working next to insulation. The insulation will provide a false sense of
security by hiding the view of the ground below the insulation.
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